The focus of this symposium will be upon the development and genetics of the vertebrate heart. This is a particularly exciting time in this field. The goal will be to discuss and clarify new paradigms which are emerging as a consequence of the study of mutations in mice, the recent cloning of genes important for cardiovascular function in humans and the identification of many genes important to embryonic heart development in the zebrafish, all coupled with ongoing elegant embryology in the chick and amphibian systems. The unitary decisions of development of the cardiovascular systems seem quite similar between zebrafish, mammal, and other species, and have led to new theories of the underlying genetic modules which establish heart form. Single gene mutations in humans have been cloned, shedding light on the underling propensities to the most common cardiovascular disorders, ranging from atherosclerosis to arrhythmias, to heart failure. New understanding of signal transduction cascades have shown unexpected similarities between the development of the heart and of other systems, especially the immune systems, and we have provided unifying hypotheses for the onset of heart failure. Genes have been described recently which are crucial to the patterning of the chamber system of the heart in the anterior-posterior and left-right directions, as well as those which direct uni-directional flow and cardiac pacemaking. Major focal points for discussion which derive from such experiments include the origin of left-asymmetry, the nature of patterning of the heart and of blood vessels, the mechanisms by which the heart deals with environmental or structural stress and which lead to heart failure, and the potential for translation of these observations into new therapies. This meeting will bring together investigators with expertise in genetics, especially those working in mouse, human, and zebrafish, embryology of the heart and vessels, cardiac and immune system transduction systems, and in vivo gene transfer, in order to exchange information in this rapidly expanding field.